CsPbIBr₂ Perovskite Solar Cell by Spray-Assisted Deposition

TLDR

Cesium metal halide perovskites are viable alternatives to organic perovskites due to their higher thermal stability. This study demonstrates a spray‑assisted solution‑processed CsPbIBr₂ perovskite solar cell. The spray‑assisted deposition sequentially processes CsI and PbBr₂, addressing bromide solubility, while substrate and annealing temperatures are optimized to improve film quality and device performance. Spraying CsI in air and annealing the film in air yield a 2.05 eV bandgap, thermally stable to 300 °C, and the optimized device reaches a stabilized 6.3 % efficiency with negligible hysteresis, with substrate temperature being the most critical factor.

Abstract

In this work, an inorganic halide perovskite solar cell using a spray-assisted solution-processed CsPbIBr2 film is demonstrated. The process allows sequential solution processing of the CsPbIBr2 film, overcoming the solubility problem of the bromide ion in the precursor solution that would otherwise occur in a single-step solution process. The spraying of CsI in air is demonstrated to be successful, and the annealing of the CsPbIBr2 film in air is also successful in producing a CsPbIBr2 film with an optical band gap of 2.05 eV and is thermally stable at 300 °C. The effects of the substrate temperature during spraying and the annealing temperature on film quality and device performance are studied. The substrate temperature during spraying is found to be the most critical parameter. The best-performing device fabricated using these conditions achieves a stabilized conversion efficiency of 6.3% with negligible hysteresis. Cesium metal halide perovskites remain viable alternatives to organic metal halide perovskites as the cesium-containing perovskites can withstand higher temperature.